1. Field of the Invention
The present invention relates to a substrate and a display panel. More particularly, the present invention relates to an active device array substrate, a liquid crystal display (LCD) panel having the active device array substrate, and a driving method of the LCD panel.
2. Description of Related Art
In recent years, an optoelectronic technology and a semiconductor device manufacturing technology become more mature, and therefore flat panel displays have been prosperously developed. Among the flat panel displays, an LCD is widely adopted to gradually replace a conventional CRT display and has become a main stream of displays in the market due to the advantages of a low operation voltage, non-radiation, light weight, small volume occupancy, and so forth.
The LCD mainly includes an LCD panel and a backlight module. The backlight module provides a planar light source (a white light source in most cases) for the LCD panel, such that the LCD is able to perform a gray-scale display function.
In terms of color performance of the LCD, a color filter layer is usually applied in the LCD panel for mixing color light beams of the backlight module, so as to display color images. For instance, in a thin-film transistor liquid crystal display (TFT-LCD), the color filter layer corresponding to each pixel is usually composed of a plurality of color photoresists. The color photoresists include red color photoresists, green color photoresists, and blue color photoresists. A dimension of each of the color photoresists and a distance among the color photoresists are not able to be recognized by human eyes. Hence, a color image comprising a mixture of different colors (red, green and blue) of visible light beams can be displayed on the LCD. Nevertheless, a light transmittance rate is reduced after the light beams pass through the color photoresists of the color filter layer, and thus the LCD has insufficient luminance.
To resolve said issue, a plurality of solutions have been proposed according to the related art. One of the solutions aims at using a light emitting diode (LED) as the light source in the backlight module. The LED is able to supply the LCD panel with the red light, the green light, and the blue light, respectively, and different colors of lights can be obtained by controlling the light transmittance rates of the light beams with different colors. Thereafter, gray scale data values of the lights with different colors are adjusted, so as to allow the LCD to display a full color image and enhance the luminance.
In detail, the aforesaid LCD must divide the time of displaying the full color image into the time of displaying the red color image, the time of displaying the green color image, and the time of displaying the blue color image. For instance, as a display frequency of the LCD reaches 60 Hz, an operational frequency of the red color image, the green color image, and the blue color image is 180 Hz, respectively. In other words, as the full color image is displayed on the LCD at 60 frames per second (during a frame time of 1/60 second), a sub-frame time of the red image, the green image, and the blue image is 1/180 second, respectively. By rapidly switching the red frame, the green frame, and the blue frame, the entire full color image can be displayed within the original frame time of the LCD. A method for rapidly switching the red image, the green image, and the blue image on an axis of time within a range of time of visual retention to form the full color image is referred to as a field color sequential (FCS) method.
By applying said FCS method, the fabrication of the color filter layer in the LCD can be omitted, and the luminance of the LCD can then be enhanced. However, when the FCS method is applied, the frame time of the LCD is reduced to one third of the original frame time. Namely, a charging time of each of the pixels is reduced to one third of the original charging time, such that display errors are more likely to occur in the LCD due to the insufficient charging time of the pixels and the insufficient response time of corresponding liquid crystals.
To resolve said issue regarding the short response time of the LCD, a plurality of solutions have been proposed according to the related art. One of the solutions is directed to an application of a specific type of liquid crystals having a relatively fast response speed, such as optically compensated bend (OCB) liquid crystals. Nonetheless, the specific type of liquid crystals brings about an increase in costs of manufacturing the LCD.
in U.S. Patent Application Publication No. 2007/0030233, a method for driving an active device array substrate sequentially is disclosed for enhancing a response speed of an LCD. In detail, please refer to FIG. 1 which is a schematic view of the active device array substrate as proposed in the U.S. Patent Application Publication No. 2007/0030233. In FIG. 1, an active device array substrate 100 includes a plurality of scan lines 10, a plurality of data lines 20, a plurality of pixel electrodes 40, and a plurality of active devices 30 for controlling each of the pixel electrodes 40. Each of the pixel electrodes 40 is electrically connected to the corresponding scan line 10 and the corresponding data line 20. In the method of sequentially driving the active device array substrate 100, a plurality of scan lines 10a, 10b, and 10c are required to be turned on at the same time, and different data voltages must be input to the different pixel electrodes 40 through a plurality of data lines 20a, 20b, and 20c simultaneously. To avoid the erroneous input of the data voltages, the plurality of data lines 20a, 20b, and 20c should be arranged within the pixel electrodes 40. Namely, the data lines 20a, 20b, and 20c pass through the pixel electrodes 40 arranged in the same column, such that the data lines 20a, 20b, and 20c are disposed below the pixel electrodes 40 in the same column. Nevertheless, said orientation easily results in occurrence of a coupling effect between the pixel electrodes 40 and the data lines 20 and occurrence of a cross-talk effect, thus negatively affecting the display quality of the LCD. On the other hand, when a number of the data lines are arranged within the pixels, an aperture ratio of the LCD is apt to be decreased.